/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/* Read a record from a random position */

#include "heapdef.h"

/*
           Returns one of following values:
           0 = Ok.
           HA_ERR_RECORD_DELETED = Record is deleted.
           HA_ERR_END_OF_FILE = EOF.
*/

int heap_rrnd(register HP_INFO *info, byte *record, byte *pos)
{
  HP_SHARE *share = info->s;
  DBUG_ENTER("heap_rrnd");
  DBUG_PRINT("enter", ("info: 0x%lx  pos: %lx", info, pos));

  info->lastinx = -1;
  if (!(info->current_ptr = pos))
  {
    info->update = 0;
    DBUG_RETURN(my_errno = HA_ERR_END_OF_FILE);
  }
  if (!info->current_ptr[share->reclength])
  {
    info->update = HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
    DBUG_RETURN(my_errno = HA_ERR_RECORD_DELETED);
  }
  info->update = HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
  memcpy(record, info->current_ptr, (size_t)share->reclength);
  DBUG_PRINT("exit", ("found record at 0x%lx", info->current_ptr));
  info->current_hash_ptr = 0; /* Can't use rnext */
  DBUG_RETURN(0);
} /* heap_rrnd */

#ifdef WANT_OLD_HEAP_VERSION

/*
           If pos == -1 then read next record
           Returns one of following values:
           0 = Ok.
           HA_ERR_RECORD_DELETED = Record is deleted.
           HA_ERR_END_OF_FILE = EOF.
*/

int heap_rrnd_old(register HP_INFO *info, byte *record, ulong pos)
{
  HP_SHARE *share = info->s;
  DBUG_ENTER("heap_rrnd");
  DBUG_PRINT("enter", ("info: 0x%lx  pos: %ld", info, pos));

  info->lastinx = -1;
  if (pos == (ulong)-1)
  {
    pos = ++info->current_record;
    if (pos % share->block.records_in_block && /* Quick next record */
        pos < share->records + share->deleted && (info->update & HA_STATE_PREV_FOUND))
    {
      info->current_ptr += share->block.recbuffer;
      goto end;
    }
  }
  else
    info->current_record = pos;

  if (pos >= share->records + share->deleted)
  {
    info->update = 0;
    DBUG_RETURN(my_errno = HA_ERR_END_OF_FILE);
  }

  /* Find record number pos */
  hp_find_record(info, pos);

end:
  if (!info->current_ptr[share->reclength])
  {
    info->update = HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
    DBUG_RETURN(my_errno = HA_ERR_RECORD_DELETED);
  }
  info->update = HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
  memcpy(record, info->current_ptr, (size_t)share->reclength);
  DBUG_PRINT("exit", ("found record at 0x%lx", info->current_ptr));
  info->current_hash_ptr = 0; /* Can't use rnext */
  DBUG_RETURN(0);
} /* heap_rrnd */

#endif /* WANT_OLD_HEAP_VERSION */
